Remember that when you are in the underwater craft you can slow yourself down to avoid crashing to your death by taking your finger off the screen.
Pay attention at the beginning of each stage as sometimes you will get a quick glimpse to where the bonus collectible called a 'bake' can be found.
Regardless of the speed you enter orbit at you will be reduced to a standard pace if you remain in it for too long. Therefore the best tactic is to enter and leave it as quickly as possible so you maintain your momentum.
Unlock Good Ending:
When you have collected the 6 cape pieces which are hidden throughout the game you will be able to see the 'Good' ending.